security: sanitize markdown output and reduce PII logging

- Add isomorphic-dompurify to sanitize rendered docs HTML and Terms of Service
- Remove addLdapUser full-object logging that included password hashes
- Log only error name/message on auth/login failures instead of full LDAP error objects

Co-Authored-By: Claude <noreply@anthropic.com>

nodejs/models/auth.js

@@ -23,7 +23,7 @@ Auth.login = async function(data){
 
 		return {user, token}
 	}catch(error){
-		console.error("AUTH LOGIN error:", error);
+		console.error("AUTH LOGIN error:", error.name, error.message);
 		throw this.errors.login();
 	}
 };